NEXT month, the Temple of Baal will come to Times Square. Reproductions of the 50-foot arch that formed the temple’s entrance are to be installed in New York and in London, a tribute to the 2,000-year-old structure that the Islamic Statedestroyed last year in the Syrian town of Palmyra. The group’s rampage through Palmyra, a city that reached its peak in the second and third century A.D., enraged the world, spurring scholars and conservationists into action. Numerous nongovernmental organizations are now cataloging and mapping damaged cultural heritage sites in the region.